Plastics

• What are the two main groups of plastics?

  Thermoplastics and Thermosetting Plastics
• What is a key characteristic of thermosetting plastics?


  They cannot be softened, shaped, or moulded by reheating
• Can thermosetting plastics be recycled?


  No, they cannot be recycled
• How do thermosetting plastics behave when heated?


  They undergo significant chemical change, becoming hard and rigid
• What happens to thermoplastics when they are reheated?


  They become weaker each time they are reheated
• Can thermoplastics be recycled?


  Yes, they can be recycled
• What is a characteristic of thermoplastics regarding heat resistance?


  They do not resist heat well
• What are some examples of thermoplastics?

  • Acrylic
  • PVC (Polyvinyl Chloride)
  • ABS (Acrylonitrile Butadiene Styrene)
  • Rigid Polystyrene
  • Nylon
• What are some examples of thermosetting plastics?


  • Melamine
  • Polyester Resin
  • Epoxy Resin
  • Urea Formaldehyde
• What is a key feature of acrylic plastic?


  Acrylic can be opaque or transparent and is hardwearing
• In what applications is acrylic commonly used?


  Display signs, baths, roof lights, and machine guards
• What are the two forms of PVC?


  Soft and flexible (plasticized) and hard and rigid (unplasticized)
• What is the use of soft PVC?


  Used for clothing and electrical cables
• What is the use of hard PVC (uPVC)?


  Used for window frames and piping
• What is a characteristic of ABS plastic?


  It is impact resistant, tough, and lightweight
• In what products is ABS commonly used?


  Toys, golf club heads, whitewater canoes, and car bumpers
• What is a characteristic of rigid polystyrene?


  It is light but strong and softens at about 95 degrees Celsius
• What are some applications of rigid polystyrene?


  Used for hollow shapes like food packaging and disposable cutlery
• What is a key feature of nylon?


  It has good wear resistance and is a good heat resistor
• In what products is nylon commonly used?


  Toothbrush bristles, fishing lines, cable ties, and ropes
• What is a characteristic of melamine?


  It is a hard, durable, heat resistant polymer
• In what products is melamine commonly used?


  Tableware, worktops, and decorative laminates
• What is a characteristic of polyester resin?


  It is strong, stiff, tough, and resistant to water absorption
• In what applications is polyester resin commonly used?


  Boat building, including yachts, kayaks, and canoes
• What is a key feature of epoxy resin?


  It has excellent adhesive properties and is moisture resistant
• In what applications is epoxy resin commonly used?


  Aerospace industry and paint
• What is a characteristic of urea formaldehyde?


  It is a stiff, non-transparent plastic with excellent tensile strength
• In what products is urea formaldehyde commonly used?


  Electrical fittings and cooker knobs
• What are the differences between thermoplastics and thermosetting plastics?


  Thermoplastics:

  • Can be reheated and reshaped
  • Can be recycled
  • Do not resist heat well

  
  

  Thermosetting Plastics:

  • Cannot be reshaped by reheating
  • Cannot be recycled
  • Resist heat and fire well